The book discusses the processes of propagation and scattering of nonlinear sound waves parametric phenomena in the acoustics of the ocean absorption and scattering of sound in a turbulent environment interaction of sound and internal waves. The results of theoretical and experimental field studies of sound scattering by hydrophysical inhomogeneities of the marine environment, bottom and sound-dispersing layers in the Pacific, Indian and Atlantic oceans, as well as in the North Seas. Features of construction and application of hydroacoustic systems with parametric antennas for oceanological research and acoustic methods for remote measurement of hydrophysical characteristics of the marine environment are considered in detail .. Spectral methods and results of laboratory studies of reverse volume sound scattering on a turbulent jet are presented . This is the third book dedicated to the work done at the Institute of Oceanology them . P. P. Shirshov RAS on nonlinear acoustics .